The MASSIVE 60cm German Siege Mortar Karl

During World War 2, the Germans were famous for designing and producing mega war artillery. One of the most notable German Mortar Guns was the Mortar Karl, an imposing machine that could fire shells of up to 2170kg and were 60cm in diameter. Its power was enough to fire lighter shells at targets at a distance of more than 10kms.

The Germans built six guns and one test gun. These colossal guns fought the most vicious of wars when they were used to attack the Soviet bastions situated at Brest-Litovsk and Sevastopol. The guns were also used to attack Polish fighters in their Capital, Warsaw.

The Mortar Karl was instrumental in the German offensive against the Allied forces when they battled in the Bulge. It is also recorded that Mortar Karl was used in their attempt to bring down the captured bridge at Ludendorff, the battle at Remagen.

Today only one Mortar Karl, the one meant for testing, exists after the other six were disposed of after the end of the war.

The German military artillery production Company, Rheinmetall, was instrumental in the conceptualization and eventual production of the Mortar Karl. In the month of March 1936, the company proposed to build an extremely weighty howitzer to bombard France’s concrete fortification popularly known as ‘Maginot Line.’

The initial concept envisaged a kind of weapon that was capable of being transported on tracked vehicles for assembly on site. However, the preparation took much longer leading to the concept changing the design of automatic artillery in the first month of 1937.

After the first production of the Karl Mortar, driving trials to test the tremendously raised ground weight and navigating such a humongous vehicle were conducted between 1938 and 1939. Firing trials were held in 1939, followed by complete driving trails in 1940.

Instrumental to the production of Mortar Karl was General Karl Becker the German weapons engineer and artillery. The gun derived its nickname from the General. The six guns and one test gun were delivered between November 1940 and August 1941.

Movement and Support

The Mortar Karl presented a logistical challenge. Having a weight of 124 tonnes and fitted with either a gasoline or a diesel engine that provided a top speed of 6.2mph, the Karl-Gerät only used the speed for aiming purposes. The plinth had just four degrees of navigation on both sides. To move any distances, it had to be dissembled into seven loads by means of a special mobile crane.

After disassembly, the chassis would be loaded onto a trailer with six axles while the other six lighter loads were placed on a trailer with four axles. Whenever they encountered a bridge not strong enough to withhold the weight of the loaded trailers, the chassis was unburdened and carried across separately.

Culemeyer-Strassenroller lowboy trailer

The chassis was loaded onto a six-axle Culemeyer-Strassenroller lowboy trailer. The other parts of the gun were lighter and used four-axle trailers. If the trailer with the chassis on board had to cross a bridge that couldn’t carry their combined weight the chassis had to be off-loaded and driven across under its own power.

A Karl-Gerät on its rail transporter

The Karl-Gerät was moved via rail for long distances. Over short distances, it would comfortably move on its own on top of the normal soil. However, driving across sSoft soil was prohibited since it could quickly lose a track

The original Mortar shells could make a 49 ft. and 16 ft. wide and deep crater respectively over a concrete wall. It could not, however, make much range because of its colossal weight.

A lighter version of the 040 was presented in 1942 and could easily cover a distance of 10km. Other versions, like the 041 with a 52cm diameter, were tested but were never used until 1944.